While most homes in an urban environment receive natural gas through a centralized distributed system throughout the city for use in heating their homes, most rural homes and farms rely on liquid fuel storage tanks installed on their property to supply the needed fuel for heating, cooking, etc. In such rural environments where a distributed pipeline system does not exist, fuel tank trucks actually deliver the fuel to the individual farms and residences, fill their onsite storage tanks, and leave. The users then draw from the tank as needed to supply their home and outbuildings with heat and for cooking, and occasionally for the generation of electricity. Often, the fuel of choice for these rural installations is liquid propane (LP), although fuel oil, natural gas, etc. may be used based on the installation and equipment installed on the farm or residence.
As the fuel in the storage tank is used for heating, cooking, etc. it will need to be refilled by the tank truck. Typically, there are two arrangements with the fuel company by which refueling is accomplished.
In a first arrangement, a rural customer contracts with the fuel company to make periodic deliveries to refuel the storage tank. Depending on the size of the tank installed at the rural location, such periodic deliveries may be scheduled weekly, monthly, etc. Typically, such deliveries are scheduled so that the customer will not have run out of fuel before the next scheduled delivery is made under an estimated maximum usage of the fuel by that customer. While such a scheduling attempts to preclude the possibility of running out of fuel in the tank, the rural customer pays a premium for such a service. This is because the rural customer often pays a fixed delivery charge regardless of the amount of fuel that is actually refilled into their storage tank. For example, if a warm spell occurs between scheduled deliveries and the user does not consume as much fuel as was estimated in establishing the delivery schedule, the rural user may actually need only a very small amount of fuel. Nonetheless, the user must pay the full delivery charge for having the fuel truck come to the installation.
Despite the premium paid by the user, such a scheduled delivery service also cannot guarantee that the user does not run out of fuel between scheduled deliveries. That is, if a particularly cold snap occurs between the scheduled deliveries or if the user simply uses more fuel during that period than has been typical, there is a possibility that the tank may run empty before the fuel truck returns to refuel the storage tank. As a result, the rural customer may be left without fuel for heating, cooking, etc.
A second type of arrangement between the fuel company and the rural customer is known as a will call arrangement. In such a will call arrangement, the user has responsibility for monitoring the level of fuel remaining in the tank and calling the fuel company to schedule the next delivery to preclude the tank from running empty. In such a will call system, the user is required to periodically check a gauge or dial installed on the storage tank to determine the amount of fuel left in the tank. When the amount of fuel drops below a certain level, the rural customer contacts the fuel company to request a delivery of fuel to refill the storage tank. Many rural customers like this will call arrangement because it minimizes the fixed delivery cost as a proportion of the amount of fuel needed to refill the tank because a delivery is only requested when refilling is necessary.
The problem with such a will call system is that it requires the user to physically go to the storage tank and read a gauge installed thereon. Since the storage tanks are not typically installed in close physical proximity to the residence, and since the largest usage of such fuel occurs during the winter and in extremely cold temperatures, the users are forced to be exposed to such cold temperatures, snow, etc. while they walk to the storage tank, read the gauge, and return to the residence. Because this chore is not pleasant during periods of extreme cold, users often put off checking their tanks. Unfortunately, the rate at which the user consumes this fuel is typically greater than normal during such periods. As a result, many users inadvertently run out of fuel before they can schedule a refill simply because they did not want to experience the unpleasantness of having to hike to their fuel storage tank during such bad weather. As a result, they may be forced to pay an extra emergency delivery charge or endure periods without heat until the delivery truck can return to refuel their storage tank.
There exists, therefore, a need in the art for a tank level monitoring system that does not require the user to endure harsh weather conditions while checking the fuel level in their tank in a will call service arrangement.